1. Field of the Invention
The present invention relates to industrial multilayer fabrics having improved rigidity and wear resistance and also having improved strength at a joining portion where yarns are joined in an endless manner by weaving. Such advantages are actualized by employing a structure in which narrower wefts of a small diameter are arranged between lower side wefts so as to sandwich therebetween a knuckle formed by warps on the lower surface side.
2. Description of the Related Art
Fabrics formed by weaving warps and wefts have heretofore been used widely as an industrial fabric, for example, papermaking fabrics, conveying belts, and filter cloths. They are required to have fabric properties suited for using purposes or using environments. Requirements for papermaking fabrics to be used in a papermaking step for removing water from raw materials by utilizing meshes of the fabrics are especially strict. For example, there is a demand for fabrics that do not easily transfer a wire mark of the fabrics to paper and are therefore superior in surface property, fabrics having a dehydration property to enable complete removal of excess water contained in the raw materials and having sufficient rigidity and wear resistance to enable suitable use of it even under severe environments, and fabrics capable of retaining conditions necessary for making excellent paper for a long period of time.
There is also a demand for fabrics having a fiber supporting property, capable of improving a papermaking yield, having size stability, and having running stability, and the like. The demand for papermaking fabrics has become severe with a recent increase in the speed of a papering machine.
Among industrial fabrics, papermaking fabrics must satisfy the most severe requirements so that description on them will promote understanding of the requirements and solutions of most of the industrial fabrics. Therefore, one example of the papermaking fabrics will hereinafter be described.
In typical industrial fabrics, fabrics are traveled by joining the fabrics, which have been obtained by weaving to have ends, in an endless manner by the conventional method, suspending them in a plurality of rollers, and travelling the rollers while applying a tension thereto.
In order to actualize this, fabrics are required to have elongation resistance, a stable shape, resistance against wear caused by the contact with the rollers, and a joining strength strong enough to prevent disconnection of a joint, which has been made endless, even in travelling under tension.
Two-layer fabrics made by weaving a closely woven fabric using yarns of a small diameter on a side contiguous to wet paper with a coarsely woven fabric using yarns of a large diameter on a side contiguous to the rollers of a machine can usually have all of surface smoothness, rigidity, and dehydration property. As an arrangement ratio of wefts is described in Examples or Claim 8 of Japanese Patent Application Laid-Open No. 2006-322109, there has conventionally been known a weft long crimp structure in which the number of lower side wefts is made smaller than that of upper side wefts to improve a dehydration property and rigidity and wefts are made responsible for wear for the purpose of improving wear resistance.